This project was put on hold over the holidays. It's always a busy time, plus the club doesn't hold meets over summer.
But I have just completed another 10 units. More of the same, but thought you guys might enjoy some more photos.
I couldn't get the same batteries as the last batch, which were 650mAh, these have much smaller 220mAh. But this still provides about 4 hours of run time.
The uBlox GPS modules are a huge improvement. Even without the SAW filter in the RF path and the sub-optimal PCB size compared to the antenna. These find more GPS satellites faster than the G.top modules, plus they also use glonass which doubles the visible satellites.

Driver code for a few boards is available from my github account. A PCB design with reduced size allows two boards to be mounted to the EK-TM4C1294XL LaunchPad providing up to 6 axes of control (needs to be verified). I have also added TCP streaming to the EK-TM4C1294XL LaunchPad but usure if I can publish the code due to the "viral" clause in many of TIs files - even the startup code 🙁. Grbl is released under GPL and I have a hard time understanding the legalese related to that...
I am currently working on a DRO/MPG for my lathe with Grbl running on a MSP432, and the DRO/MPG code on a Tiva C/MSP430 combo. Threading support is a part of that work and hopefully I'll be able to get it working reliably - looks promising this far.

Check the usual suspects:
Is the I²C bus initialised?
Wire.begin();
Does the I²C device run at 3.3V?
Otherwise, use a logic-level converter.
Are pull-ups installed?
Try 10, 4.7 or 2.2 kΩ for the SDA and SCL lines.
In case the LaunchPad provides multiple I²C ports, is the correct port selected?
Try
Wire.setModule(0); // or other port number
Wire.begin();
Still nothing?
Use a logic analyser to trace the signals on the I²C port.
(To be continued...)

Although all the LaunchPads feature a programmer-debugger, sometimes an external one might be useful.
Segger has just launched the J-Link EDU Mini, with all the software and expertise of Segger, priced at just USD18!
I'm very happy with the larger Segger J-Link Edu priced at USD60.
I've ordered one J-Link EDU Mini and plan to review it.

The example msp430fr5994x_lpm4-5_02.c is supposed to show how little current is used in this mode.
In the file it says:
// MSP430FR5x9x Demo - Entering and waking up from LPM4.5 via P1.3 interrupt
// with SVS disabled
//
// Description: Download and run the program. When entered LPM4.5, no LEDs
// should be on. Use a multimeter to measure current on JP1 and
// compare to the datasheet. When a positive voltage is applied
// to P1.3 the device should wake up from LPM4.5. This will enable
// the LFXT oscillator and blink the LED (on P1.0).
Even for a high-end multimeter this current is too low to be accurately measured.
So I helped myself this way:
- power the processor from the supercap
- a 10k resistor with two antiparallel diodes act as a shunt,
- connect the volt meter across the supercap, not across the processor
0.43mV over a 10k resistor gives 43 Nanoamps. (!) Yes, the datasheet (page 32) is right, typical value at 25°C is 45nA.
A CR2032 (200mAh) cell would allow the processor to wait for an interrupt for 530 years.

My compact Lisp interpreter, uLisp, now supports the MSP430F5529 and MSP430FR5969 LaunchPads.
As well as supporting a core set of Lisp functions, uLisp includes Arduino/Energia extensions, making it ideal as a control language for the MSP430.
For more information see http://www.ulisp.com/.

I went to Sears yesterday to get my new lawn mower and I got a free gift, Kenmore Alfie Voice-Controlled Intelligent Shopper.
The regular price of Alfie is $49, but they are now on sale for $25. However, if you are SYW member and you spend more than $25, you get one for free (expires 7/1/17!)
BTW, I also found Alfie for $7.95 on Amazon (with free Prime shipping, even cheaper from other vendors.)
What's the big deal about Alfie? Crack one open and you will find the following:
CC3200R1 Single-Chip Wireless MCU (with W25Q32JV (32M-bit) serial Flash memory from Winbond and a chip antenna)
TLV320AIC3100 Low-Power Audio Codec With Audio Processing and Mono Class-D Amplifier
3.7V 500mAh LiPo battery
12 WS2812B LEDs
Other useful things are microphone, large speaker, 2 LEDs, 2 switches, and USB port
In other words, IoT experimenter's treasure chest!
Can't wait to hack that thing (there's what appears to be programming header on the board.)